pfscat man page

Read number of frames as input, stitch them either horizontally or vertically, and produce single frame as output. If frames are not all the same size they are justified with each other - by default they are centered, but can also be flushed with a specified edge.

Stitch two hdr animations in vertical alignment. 'pfscat' is taken as an argument by 'pfsinmulti', therefore it must be preceded with '--'. Number of @1 @2 ... @n arguments must be the same as number of animations to combine.